The inventive concept relates generally to methods of driving a nonvolatile memory device.
The threshold voltage of programmed nonvolatile memory cells in certain nonvolatile memory devices and systems tend to change over time. There are many reasons for this adverse result having to with environmental factors, operational factors, and basic properties of materials used to fabricate the nonvolatile memory cells.
It not acceptable to have the threshold voltages of programmed nonvolatile memory cells to materially change over time, because the resulting “changed” threshold voltages may be misinterpreted, thereby resulting in read data errors.